The long-term objective of this research is to study forebrain mechanisms involved in the initiation of movements. At the present stage, microelectrode recordings are made in the thalamus of alert cats: patterns of single neuron activity in the region of the internal medullary lamina (IML) are explored in relation with the occurrence of eye movements. Neuronal correlates of visuomotor integration are sought by analyzing (1) the cell firing accompanying eye movements of different natures: spontaneous, orienting, following, exploring and anticipating, (2) the responses evoked in the same neurons by visual stimuli, and (3) the interaction between stimuli and movements. The study also aims at determining the functional connections of IML neurons with other structures involved in the control of the gaze. BIBLIOGRAPHIC REFERENCES: Fuller, J. M. and Schlag, J. D. Determination of antidromic excitation by the collision test: Problems of interpretation. Brain Res. 1976, 112: 283-298. Schlag, J. and Schlag-Rey, M. Thalamic unit activity associated with visual orientation in cat. Neurosci. Abstr. 1976, p. 281, abstr. 404.